Operational amplifiers are well-known and mostly used building blocks for analog circuit design. However, due to their limited performance, researchers look for better alternatives and other active blocks. As a result, there is significant amount of past and on-going research about new current-mode active building blocks such as operational transconductance amplifiers (OTA), second generation current conveyors (CCII), current-feedback op-amps (CFOA), four terminal floating nullors (FTFN), differential voltage current conveyor (DVCC), differential difference current conveyor (DDCC), third-generation current-conveyor (CCIII), dual X current conveyors (DXCCII), current controlled current conveyors (CCCII), current differencing trans conductance amplifiers (CDTA) etc. Using these new active elements for analog design and implementing them in CMOS technology designers have acquired new possibilities to solve classic opamp based problems such as bandwidth, slew-rate etc. Moreover, active-only and MOS-only topologies provide further solutions for analog circuit design. Additionally, usage of FGMOS transistors in analog circuits is an alternative approach whose efficiency has been shown recently. This paper discusses these new possibilities in analog circuit design including applications on communication, measurement and RF systems, combining the main features for the circuit design with actual circuit realizations and demonstrating several performance limitations on chosen circuit examples. View full abstract»

In this paper, a new soft switching buck converter is presented. This converter has no extra switch in order to achieve soft switching condition. This contributes to simpler converter control circuit. The converter operation is only based on resonances between two small inductors and a small capacitor. As a result, the size and weight of converter is reduced. The converter operating modes are described and the simulation results are presented to verify the converter analysis. View full abstract»

This paper deals with the design of a rail-to-rail operational amplifier (OPAMP) for a digital-to-analog converter. To achieve a low input offset of the OPAMP, a digital offset cancelation method has been proposed and used. The offset voltage in the range from -1.4 mV to 1 mV can be achieved. The OPAMP and additional hardware were designed in 90nm CMOS technology. View full abstract»

An analysis of Fuel Cell Hybrid Power Source (FCHPS) that operates efficiently under dynamic load was presented in this paper. Hybridization of a FCHPS is made by using an Energy Storage System (ESS). The ESS uses a passive hybrid topology of batteries and ultracapacitors to take the advantages of both devices related to high density of energy and power, respectively. This kind of powerful ESS is able to assure the power balance on ESS bus, supplying dynamic load such as FC vehicles (FCVs). For high efficiency operating of the FC system, a Maximum Power Point (MPP) controller is used to generate the reference current for boost power converter. Operating of the FCHPS at MPP is shown by simulation performed. View full abstract»

An analysis of the Fuel Cell Hybrid Power Source (FCHPS) for pulsed current loads was presented in this paper. Usually, hybridization of a FCHPS is made by using either a batteries or an ultracapacitors stack, but using both devices together can provide a powerful Energy Storage System (ESS) with the features of both high energy density and high power density, which is significant for FC vehicles (FCVs). The traction motors of FCVs are supplied via inverter systems from the FCHPS and represent a Pulsed Current (PC) load for it. Also, the FC is usually connected to the ESS voltage bus via a boost power converter and represents a PC source for the ESS voltage bus. Modeling and designing of the FCHPS are demonstrated by simulation performed. View full abstract»

This paper describes the analysis of the performance of MLLR-based speaker adaptation in a large vocabulary continuous speech recognition system. Two different approaches of clustering in MLLR-adaptation with more regression classes, knowledge-based clustering and automatic clustering were analysed. The contribution of mentioned acoustic model adaptation using these two clustering approaches were compared based on the word error rate ratio (WERR) of target LVCSR. Realized study proved that the knowledge-based clustering may bring improvement comparable to the tree-based clustering, when only a few transformation classes are manually defined. View full abstract»

The following text describes in detail design of frequency filters using synthetic immittance elements of higher order with current conveyors. The paper moves on the theoretical level and offers a description of alternative method for frequency filters design. The theory of synthetic immittance elements, their design process and theory of current conveyors are described too. In conclusion, there is demonstrated possible application of proposed synthetic element by the realization of frequency filter - low pass of 2nd order. The actual proposed solution analysis results are verified using PSpice simulation. View full abstract»

There is no doubt that electromobility will be the future. All-electric vehicles were already available on the market in 2011 and 14 new vehicles will be commercially available in 2012. Due to the fact that automotive applications are influenced by the safety requirements of the ISO 26262, nowadays the use of new technologies requires more and more understanding for fail-safe and fault-tolerant systems due to increasingly complex systems. The safety of electric vehicles has the highest priority because it helps contribute to customer confidence and thereby ensures further growth of the electromobility market. Therefore in series production redundant hardware concepts like dual core microcontrollers running in lock-step-mode are used to reach ASIL D requirements given from the ISO 26262. In this paper redundant hardware concepts and the coded processing will be taken into account, which are listed in the current standard ISO 26262 as recommended safety measures. View full abstract»

This paper deals with the preparation and the design of a tool (system) for evolutionary design of circuits. The author discusses fundamental parts of the proposed design system. The paper also introduces already implemented parts of the system and presents the possibilities of this tool. The introduced design system aims to speed up and simplify the process of the evolutionary design. In future, the tool should work as a support for automated generation of source codes for an easy implementation of result circuits in FPGA devices. View full abstract»

This article deals with the object detecting methods used for the eye detection. At first is described the Haar feature-based cascade classifier object detector. Further is described the developed eye detection system working on the embedded platform and the implementation of this object detector in the OpenCV library. Finally is described proposed realized implementation in the ARM based development kit and the achieved results. View full abstract»

One of the main problems of the widely used Orthogonal Frequency Division Multiplexing is the high peak-to-average power ratio of the transmitted signal. This paper presents a new hybrid peak-to-average power ratio reduction technique, which combines a selective mapping method with a tone reservation method. The paper highlights the performance and advantages of the proposed technique and compares it with other existing methods. View full abstract»

One of the main problems of the widely used Orthogonal Frequency Division Multiplexing systems is the high peak-to-average power ratio of the transmitted signal. This paper presents a new hybrid peak-to-average power ratio reduction technique, which combines the clipping method with a new signal compression function. The paper highlights the performance and advantages of the proposed technique and compares it with other existing methods. View full abstract»

This contribution presents a study on feedback training using a motor-imagery based brain-computer interface (BCI). In contrast to majority of BCI papers focusing on development of complex signal processing methods, we used the simplest possible available methods to focus on influence of the feedback itself and development of methodology how to conduct the experiments to support user training. We have shown that simple signal processing methods are not only sufficient to achieve high-speed control but their usage is desired in online applications as the simple methods can be more easily adapted. We have introduced a novel adaptive threshold classification approach. Classification scores up to 100 % (75 % in average over all subjects and sessions) were achieved with classification of left and right arm motor imagery and visual feedback in experiments performed in synchronous manner and asynchronous self-paced operation was reached with few proficient subjects. View full abstract»

In this paper, nonideal effects of transistors on log domain filters are investigated. First order class A log domain filter is synthesized as an example. The state space synthesis method is used for design procedure. Transistors are modeled for finite current gain by using dependent current sources. Each ideal transistor is replaced with modeled ones which have finite current gain. The effects of finite current gain of each transistor are obtained as an extra term in the state space equations. Then, these extra terms are superposed in order to obtain the effects of all transistors which have finite current gain. In order to verify the validity of the offered method, the results obtained from MATLAB and the simulation results obtained from PSpice are compared. View full abstract»

Safety of multi-process embedded systems is of a great concern in majority of embedded and real-time applications. Our work deals with a multiple hardware watchdog timer device that is intended to improve the safety and reliability of multi-process systems. This paper deals with the implementation and testing of the prototype architecture using an FPGA device Spartan-3A.. View full abstract»

This paper deals with our research analyzing the influence of sound on human brain activity. Described experiment was performed on four subjects. The sound sequence consisted of six 40 s long tracks with different content was prepared as a WAV file and compressed to MP3 format with three different bit rates - 192 kb/s, 128 kb/s and 32 kb/s. Subjects were listening to the original sequence and compressed sequences with a decreasing bit rate. While they were listening to the sequences their electroencephalogram (EEG) was monitored by four channel device. The influence of decreasing bit rate on extracted EEG has been analyzed in time and frequency domain, energies were calculated. View full abstract»

This paper solves problems of influence and immunity from the voltage drop of the power supply to the electric drive. There are reflected opportune control algorithms for the quickly to change of working regime from full load in regime “drive” to “no-load” regime and opportune control algorithms for quickly to return to original working. There are also referenced the variants of adaptation of power circuits. View full abstract»

In this paper, the dynamic supply current test (IDDT) for logic circuits is presented, where the targeted defects are weak opens in regular structures (SRAM arrays). Considerations about the current based tests are made, and a method of IDDT sensor realization is presented. The method is based on conversion of the current waveform to a voltage waveform. Also the most effective parameters of both the dynamic supply current waveform and voltage waveform are analyzed and evaluated. View full abstract»

All electronic equipment where large S/N ratio is requested for the signal processing is very sensitive on disturbances coming from power supplies. This is especially true for high accuracy measurement equipment. Then simple solution is to feed such equipment from accumulators or batteries; nevertheless, this brings problems with their servicing. This contribution presents the results of study of noise disturbance of laboratory power supply on high pure sine-wave signal source and describes a design of realized special power supply with minimum noise. View full abstract»